#define _CRT_SECURE_NO_WARNINGS 1
//三角形判断
#include<stdio.h>
int main()
{
	int a = 0;
	int b = 0;
	int c = 0;
	int t = 0;
	while (scanf("%d %d %d", &a, &b, &c) != EOF)
	{
		if (a < b)
		{
			t = a;
			a = b;
			b = t;
		}
		if (a < c)
		{
			t = a;
			a = c;
			c = t;
		}
		if (b < c)
		{
			t = b;
			b = c;
			c = t;
		}
		//前三个if用来判断abc的大小，如果abc中较小的两个之和大于最大的，那么肯定满足任意两边之和大于第三边
		//如果abc中较大的两个数之差小于最小的边，那么也肯定满足任意两边之差小于第三边
		if (b + c > a && a - b < c)
		{
			if (a == b && a == c)
			{
				printf("Equilateral triangle!");
			}
			else if ((a == b && a != c) || (a == c && a != b) || b == c && a != b)
			{
				printf("Isosceles triangle!");
			}
			else
			{
				printf("Ordinary triangle!");
			}
		}
		else
		{
			printf("Not a triangle!");
		}
		printf("\n");
	}
	return 0;
}